This invention relates to braiding machines with a drive system comprising a gear belt which meshes with drive gears to provide a synchronized drive and which operates with reduced friction. The invention further relates to braiding machines having direct adjustable transmission drives between the drive motor and the take-up and the bobbin drives.
The braiding machine of the invention is very adapt at manufacturing items which are normally manufactured by small operations sometimes having only one or two machines as well as large operations. Typical articles formed by the machine of the invention are shoe laces, ropes, packing tapes, and fish nets although the machine is clearly not limited to such articles.
Common round braiding machines have long been known to the industry. Normally, these machines are restricted in production due to the friction between the drive gears which act to move the yarn carriers about the circular bed. An effort to increase the speed and reduce the friction was attempted by U.S. Pat. No. 4,913,028 which substituted a belt and pulley drive for the drive gears. This drive, not being positive, could not maintain synchronous motion between the machine elements.
It is known to provide drives for varying the rate or RPMs of both the braiding assembly and the take-up of braiding machines. For inexpensive machines which are normally used in small one, two, or three machine operations this procedure comprises changing the gear ratios in the drive train. The machine must be stopped during this procedure, which is costly and time consuming. Also, it is difficult to obtain accurately very small changes.
Another known method is by electrical controls which use sensors to vary motor speeds. U.S. Pat. No. 4,266,461 to Molitors; U.S. Pat. No. 4,716,807 to Fischer; U.S. Pat. No. 5,417,138 to Morris, Jr. et al; and U.S. Pat. No. 5,566,604 to Sperling et al generally illustrate this adjustment method.
The electronic procedure is both expensive at purchase and during operation as the life of the electric drive motors is greatly reduced. These machines are generally used in large operations as they are labor saving.
The instant arrangement is both inexpensive to purchase and finds utility in small operations.
The disclosures of the above referred to patents are incorporated with the instant disclosure.
Another object of the invention is a variable speed drive for a braiding machine which is low cost.
Another object of the invention is a braiding machine in which the driven speed and the take-up speed may be adjusted during operation.
Another object of the invention is a braiding machine in which a position drive system provides the drive for the yarn carriers and the take-up.
Another object of the invention is a braiding machine in which the output speed for the yarn carriers and the speed of the take-up is individually controlled.
Another object of the invention is a braiding machine in which the yarn carriers and the take-up are driven by a single motor and two drive systems.
Another object of the invention is a braiding machine in which loop size in the braid being formed is adjustable during braiding.
Another object of the invention is a braiding machine in which the take-up and/or the yarn carriers are sequentially adjusted during machine operation.
The instant invention is directed to a braiding machine having a braiding assembly which comprises a plurality of yarn carriers moving about a bed to interlace yarns to form a braided fabric, a take-up comprising take-off rolls engaging and drawing off the just braided fabric, and a drive for driving the braiding assembly about the bed and the take-off rolls of the take-up. The drive includes a drive train connecting the braiding assembly and the take-up with a power source. The drive train includes a first mechanical variator having a control knob, interposed between the braiding assembly and the power source for driving the yarn carriers about the bed, and a second variator, having control knob, connected with the power source for driving the take-off rolls, the take-up. The first variator control knob is operative to adjust the rate at which the yarn carriers are driven about the bed during operation of the braiding machine so that a desired rate of braiding may be selected. The second variator control knob is operative to adjust the rate of rotation of said take-off rolls of the take-up thereby adjusting the rate at which the formed fabric is drawn off, which rate determines the pitch or loop size of the forced braided fabric. The first and second variators individually rotate to achieve these desired rates of rotation.
The power source comprises two electric motors directly engaged with each of the variators or the power source may include a single electric motor directly engaged with the first variator and connected the said second variator through a second drive. The second drive comprises a pair of gear pulleys of equal pitch engaged with a gear belt which causes the electric motor to drive the first and second variators at equal rates.
The invention also includes the method of adjusting the rate of braiding and take-up in a braiding machine for achieving a selected pitch for a fabric formed on the braiding machine and for obtaining the maximum production capacity for the braiding machine. The method includes activating the braiding machine to operate at a preselected speed, adjusting the rate of take-up while continuously operating the braiding machine until the desired pitch in the fabric being formed is achieved, and then simultaneously and equally adjusting the rate of take-up and the rate of braiding until the maximum effective braiding rate is achieved.